【SSM】SSM框架整合

1、SSM框架整合

1.1、环境需求

IDEA
MySQL 5.7.XX
Tomcat 9
Maven 3.6

1.2、SSM 项目基础结构

1.2.1、Mavem 项目建立

新建一个普通的Maven项目即可

1.2.1.1、项目依赖

<dependencies>
    <!--  JSON 解析-->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.12.4</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.20</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.13.2</version>
        <scope>test</scope>
    </dependency>

    <!--  java jsp-->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>2.5</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.1</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>

    <!--  Mysql-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.47</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.7</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>2.0.6</version>
    </dependency>

    <!--  数据源-->
    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.5</version>
    </dependency>

    <!-- Spring-->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.7</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.3.9</version>
    </dependency>
</dependencies>

1.2.1.2、静态资源导出

<build>
    <!-- 修改Maven工程的 JDK版本 ：1.8 -->
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.8.1</version>
            <configuration>
                <target>1.8</target>
                <source>1.8</source>
                <encoding>UTF-8</encoding>
            </configuration>
        </plugin>
    </plugins>
    <!-- 解决静态资源导出-->
    <resources>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>false</filtering>
        </resource>
        <resource>
            <directory>src/main/resources</directory>
            <includes>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
            <filtering>false</filtering>
        </resource>
    </resources>
</build>

1.2.1.3、数据库

CREATE DATABASE `ssmbuild`;

USE `ssmbuild`;

DROP TABLE IF EXISTS `books`;

CREATE TABLE `books` (
  `bookID` INT(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
  `bookName` VARCHAR(100) NOT NULL COMMENT '书名',
  `bookCounts` INT(11) NOT NULL COMMENT '数量',
  `detail` VARCHAR(200) NOT NULL COMMENT '描述',
  KEY `bookID` (`bookID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8

INSERT  INTO `books`(`bookID`,`bookName`,`bookCounts`,`detail`)VALUES 
(1,'Java',1,'从入门到放弃'),
(2,'MySQL',10,'从删库到跑路'),
(3,'Linux',5,'从进门到进牢');

1.2.1.4、applicationContet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
    <import resource="classpath:spring-dao.xml"/>
    <import resource="classpath:spring-service.xml"/>
    <import resource="classpath:spring-mvc.xml"/>
</beans>

1.3、Mybatis层

database.properties

jdbc.driver=com.mysql.jdbc.Driver
# 如果使用的 Mysql8.0+，增加时区配置
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8
jdbc.username=root
jdbc.password=123456

1.3.1、spring-dao.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 关联数据库文件 database -->
    <context:property-placeholder location="classpath:database.properties"/>

    <!-- c3p0 连接池-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>

        <!-- c3p0连接池的私有属性 -->
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <!-- 关闭连接后不自动commit -->
        <property name="autoCommitOnClose" value="false"/>
        <!-- 获取连接超时时间 -->
        <property name="checkoutTimeout" value="10000"/>
        <!-- 当获取连接失败重试次数 -->
        <property name="acquireRetryAttempts" value="2"/>
    </bean>

    <!-- sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

    <!-- 配置 dao 接口扫描包-->
    <bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer" >
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <property name="basePackage" value="com.xg.mapper"/>
    </bean>
</beans>

1.3.2、mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <setting name="logImpl" value="COMMONS_LOGGING"/>
    </settings>

    <typeAliases>
        <package name="com.xg.pojo"/>
    </typeAliases>

    <mappers>
        <package name="com.xg.mapper"/>
    </mappers>
</configuration>

1.4、Service层

1.4.1、spring-service.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

    <!--  扫描service包下 注解-->
    <context:component-scan base-package="com.xg.service"/>
    <context:annotation-config/>

    <!--  配置 事务-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!-- 注入 数据源-->
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!-- 将 我们们的所有 业务类注册到spring
        可以通过配置或者, <bean id="" class="">
        注解实现 @Service
    -->
</beans>

1.5、Web 层

1.5.1、添加Web框架

1.5.2、web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <!--  视图解析器-->
    <servlet>
        <servlet-name>app</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <!-- 一定要注意 绑定的文件 applicationContext.xml-->
            <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>app</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--字符编码过滤器 -->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <session-config>
        <!-- session 过期时间-->
        <session-timeout>15</session-timeout>
    </session-config>
</web-app>

1.5.3、spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
    <!-- 开启注解支持， 静态资源过滤 -->
    <context:component-scan base-package="com.xg.controller"/>
    <mvc:default-servlet-handler/>
    <mvc:annotation-driven>
        <!--JSON 乱码问题-->
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

    <!-- 视图解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

1.6、最后配置

1.6.1、配置 Tomcat

1.6.2、添加 lib

1.6.3、books.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
    <style>
        .table {
            line-height: 1.6;
            font: 14px Helvetica Neue, Helvetica, PingFang SC, Tahoma, Arial, sans-serif;
            -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
            border-collapse: collapse;
            border-spacing: 0;
            margin: 10px 0;
             30%;
            background-color: #fff;
            color: #666;
        }
        .table th{
            text-align: left;
        }
    </style>
</head>
<body>
<table class="table">
    <thead>
    <tr>
        <th style=" 100px">书籍编号</th>
        <th style=" 180px">书籍名称</th>
        <th style=" 120px">书籍数量</th>
        <th style=" 250px">书籍详情</th>
    </tr>
    </thead>
    <tbody>
    <c:forEach var="book" items="${booksList}">
        <tr>
            <td>${book.bookID}</td>
            <td>${book.bookName}</td>
            <td>${book.bookCounts}</td>
            <td>${book.detail}</td>
        </tr>
    </c:forEach>
    </tbody>
</table>
</body>
</html>

1.6.4、测试 Controller

BooksController

package com.xg.controller;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.xg.service.books.BooksServiceImpl;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.HashMap;

@RestController
public class BooksController {

    private final ObjectMapper objectMapper = new ObjectMapper();

    private final BooksServiceImpl booksService;

    public BooksController(BooksServiceImpl booksService) {
        this.booksService = booksService;
    }

    @RequestMapping(value = "getBooksListJSON", produces = "application/json")
    public String getBooksListJSON() throws JsonProcessingException {
        return objectMapper.writeValueAsString(booksService.queryBooks());
    }

    @RequestMapping(value = "getBooksListJSON02", produces = "application/json")
    public String getBooksListJSON02() throws JsonProcessingException {
        HashMap<String, Object> map = new HashMap<>();
        map.put("booksList", booksService.queryBooks());
        map.put("username", "遇见星光");
        map.put("count", 10);
        map.put("page", 1);

        return objectMapper.writeValueAsString(map);
    }

}

> BooksController02

```java

package com.xg.controller;

import com.xg.pojo.Books;
import com.xg.service.books.BooksServiceImpl;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.List;

@Controller
public class BooksController02 {

    private final BooksServiceImpl booksService;

    public BooksController02(BooksServiceImpl booksService) {
        this.booksService = booksService;
    }

    @RequestMapping("/allBooks")
    public String queryBooksList(Model model) {
        List<Books> booksList = booksService.queryBooks();
        model.addAttribute("booksList", booksList);

        return "books";
    }
}

1.6.3.1、结果

http://localhost:8080/ssm_01/getBooksListJSON

http://localhost:8080/ssm_01/getBooksListJSON02

http://localhost:8080/ssm_01/allBooks

1.7、排错思路

1.7.1、问题：bean不存在

步骤：

查看这个bean注入是否成功
Junit单元测试，看我们的代码是否可以查询出结果
问题，一定出在底层，是spring出了问题
springMVC，整合的时候没有调用到我们的service层的bean
1. applioncationContext.xml 没有注入bean
2. web.xml 中，我们也绑过配置文件！，发现问题我们配置的是 spring-MVC.xml
  
  这里面确实没有 service bean ，所以空指针异常

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原文地址：https://www.cnblogs.com/Right-A/p/15103783.html

【SSM】SSM框架整合

1、SSM框架整合

1.1、 环境需求

1.2、SSM 项目基础结构

1.2.1、Mavem 项目建立

1.2.1.1、 项目依赖

1.2.1.2、静态资源导出

1.2.1.3、数据库

1.2.1.4、applicationContet.xml

1.3、Mybatis层

1.3.1、spring-dao.xml

1.3.2、mybatis-config.xml

1.4、Service层

1.4.1、spring-service.xml

1.5、Web 层

1.5.1、添加Web框架

1.5.2、web.xml

1.5.3、spring-mvc.xml

1.6、最后配置

1.6.1、配置 Tomcat

1.6.2、添加 lib

1.6.3、books.jsp

1.6.4、测试 Controller

1.6.3.1、结果

1.7、排错思路

1.7.1、问题 ：bean不存在

1.1、环境需求

1.2.1.1、项目依赖

1.7.1、问题：bean不存在